What Is a Linked List?

A chain of nodes

A linked list stores each item in its own node. A node holds a value and a pointer to the next node. The first node is the head; the last one points to nullptr.

Think of it like this: A treasure hunt: each clue tells you where the next clue is. You can't jump to clue 5 – you follow 1, 2, 3, 4.

#include <iostream>
using namespace std;

struct Node {
    int value;
    Node* next;
    Node(int v) : value(v), next(nullptr) {}
};

int main() {
    // build 10 -> 20 -> 30
    Node* head = new Node(10);
    head->next = new Node(20);
    head->next->next = new Node(30);

    for (Node* cur = head; cur != nullptr; cur = cur->next)
        cout << cur->value << " -> ";
    cout << "nullptr" << endl;
    return 0;
}

Output

10 -> 20 -> 30 -> nullptr

• new Node(10) creates a node in memory and gives back its address (a pointer).
• head->next means “the next field of the node head points to”.

Array vs linked list

Tip: The standard library has std::list (doubly linked) and std::forward_list. Writing your own teaches you pointers – and interviews love linked list questions.